1. Field of the Invention
The present invention relates to fluid dispensing devices and more particularly, but not by way of limitation, to a gasless, one-piece pressure dispensing tubular unit of elastomeric material, the pressure of which is created by the elastomeric properties of the material after the unit has been expanded by forcing fluid products into the unit under pressure.
2. History of the Prior Art
Pressurized containers for dispensing fluids have achieved a high degree of popularity for handling many types of fluids ranging from sprayable liquids to extrudable viscous fluids. In the prior art, most of the dispensers have utilized a propellant gas for pressurizing the fluid. The cost of the propellant gas is a considerable part of the cost of the device and occupies much of the space that could be used for housing the product. Further, the chemical nature of the propellant gasses used has been found and is believed to be damaging to the environment.
Efforts have been made to utilize elastic bags for the dispensing of fluid in order to obviate the use of propellant gasses. Typical of these attempts are teachings found in the patent to Kain, U.S. Pat. No. 3,940,026, issued Feb. 24, 1976 to Calvin L. Kain.
There has been extreme difficulty in attaching such elastomeric bags to existing valve structures to prevent damage to the bag itself and provide an effective system for dispensing the product.
Further, in the case of elastic bags having uniform cross-sectional shape, the bags tend to expand only in the middle part thereby filling only a portion of the bag leaving the ends unexpanded similar to that experienced in blowing up a new balloon wherein the end portion does not become filled with air.
The net result of these efforts has left the propellant gas dispensing units on the market, along with hand-operated pumps, which are less convenient to use and more difficult to manufacture due to the moving parts associated with such pumps.